Donald Trump and Kim Jong Un will meet for the first time in a few weeks.

The US president hasn't insulted Kim on Twitter in nine weeks, as North Korea has ratcheted down its nuclear activity and held talks with South Korea.

It shows how rhetoric between the two nations has cooled significantly.

Donald Trump and Kim Jong Un will meet face-to-face for the first time this year, in what will be a historic moment. But the encounter, set to take place before May, hasn't been a bolt from the blue.

The US president has significantly toned down his fiery rhetoric against North Korea in 2018. Kim's regime, meanwhile, has slowed down nuclear development, halted missile tests, and engaged with South Korea during the Winter Olympics.

One of the easiest places to see the changing dynamic between Trump and Kim is the US president's Twitter feed. Once the front-line for America's anti-North Korea rhetoric, Trump has been notably quiet on the issue in recent months.

Trump at his UN speech, where he referred to Kim as "rocket man" in front of hundreds of diplomats. Drew Angerer/Getty Images

Trump's North Korea rants hit their height between August and October last year, when he repeatedly called Kim "rocket man," described him as "a madman," and threatened North Korea with "fire and fury."

Two days after the country flew a missile over Japan, Trump called Kim "rocket man" for the first time. Trump proceeded to use that nickname at least six times after that — once in a speech to the UN General Assembly on September 19, and five more times on Twitter.

After the Winter Games, North and South Korea met face-to-face, Kim promised to give up his nuclear weapons, and said he wanted to meet Trump. Trump praised the "serious effort" being made.

That same meeting also spurred South Korean officials to invite Trump to meet Kim in North Korea for the first time, which he accepted. Trump tweeted, in response, that "great progress [was] being made."

Whether the Trump-Kim meeting will lead to denuclearization or sanctions relief is unclear at this point. While Trump has been praised for leading a diplomatic coup, critics also caution that Kim may be entering meetings just to gain sanctions relief, only to back out at the last minute.

Whichever way the talks go, you can bet the US president will be tweeting about it.